# Thread: y = mx + b problems

1. ## y = mx + b problems

Hey guys,
I'm really stumped on a couple of these problems and was wondering if someone could offer some advice.

y = 3(1-x)
x - y = 0

The object of these problems is to find if they are things like:

-Diagonal line of slope = -1
-Vertical line
-Diagonal line of slope = 1
-Horizontal line

Thanks!

2. Hey..
If you try to rewrite the two equations in the form $\displaystyle y=ax+b$ then you will get:
$\displaystyle y = -3x+3$
$\displaystyle y = x$
You know that the slope is the coefficient of x i.e. the number a.
for the first question, no equation has a slope of -1
for the second question, you have to know that a vertical line has a slope of infinity and it can't be represented in the form $\displaystyle y=ax+b$. It is rather represented as $\displaystyle x=k$. So no equation from the given satisfies this condition.
for the third question, you can see that the second equation $\displaystyle y = x$ has a slope of 1.
for the fourth question, you have to know that a horizontal line has a slope of 0 and it is represented as $\displaystyle y=m$. So, no equation from the given satisfies this condition.